From my point of view absolutely top priority is to kill '2k' heroes, especially after exploit discovered.
if stable, artifact effects or object effects persist or not is completely secondary. At least disallowing object effects is consistent (so MP from slowest unit + artifacts is OK). Stable is questionable at this point, I would not mind to keep the effect, but this is not thing of great importance.
Killing heroes permanently or reseting their skillsets is other discussion for me.
Fix should focus on removing 2k and block currently discovered exploit.